Shielded hypodermic syringe



March 10, 1959 R. A. WHITE 2,876,770

' SHIELDED HYPODERMIC SYRINGE l Filed Oct. 10, 1955 INVEN TOR.

United States SHIELDED HYPODERMIC SYRINGE l Raymond A. White, San Pedro, Calif.

Application October 10, 1955, Serial No. 539,419

4 Claims. (Cl. 12S-215) This invention relates to a hypodermic syringe and is particularly concerned with a shield for covering the needle thereof, it being a general object of this invention to provide a retractable needle shield that normally hides the needle from view and which yieldingly shifts its position in order to allow the needle to penetrate cutaneous tissue.

The typical syringe has long been used to effect subcutaneous injections and is characterized by a plunger operated device that carries a slender tubular needle and passes liquid into the body tissue.` The general purpose and effect of such devices is well known to most individuals and since the resulting sensations are not altogether pleasant, thetechnicians who apply said device tosaid individuals encounter serious handicaps. For example, a great many individuals actually fear being subjected to a hypodermic needle and are adversely affected and excited. Due to excitement, many individuals become faint apparently due to the mere sight of the needle and dueto the thought of `impending pain, although the pain is usually only slight.

`It is an object of this invention, in view of the foregoing circumstances, to provide means for excluding from view, the syringe needle which obviously atfects individuals to such a great extent that they overanticipate the painful effect of the needle. With the Structure that I have provided, it is conveniently possible for physicians or dentists to bring the syringe needle into contact with the body of an individual without his prior Aknowledge that such action is taking place.

Itis also an object of this invention to provide means for' stabilizing and guiding the needle in order to minimize breakage thereof, and to protect and cover the needle during sterilizing operations when the syringe comes into contact with other instruments of various kinds. Further, the needle will not become dulled or bent. """It is another object of this invention to provide a structure of the character referred to wherein the shield of'the structure is normally yieldingly held in an extended position so that the syringe needle is hidden from view and which shifts to expose the said needle whereupon the needle isA free to enter the body tissue. ""'Itis still another object of this invention to provide an adjustable stop or control for positioning a shield ir'rorder to control or limit the penetration of the syringe needle' thus eliminating the necessity of a plurality of needles of different lengths in order to gain rdilferent 'depths of penetration.

yAn object of this invention is to provide a simple inexpensive practical construction of the character referred to which is easily kept in a good operation and Asanitary condition. n "Thevai'ious objectsand features of my invention will be *fully understood from the following detailed descrip- :tin bf typicalrpreferred.forms and applications of my jinvwn'tion, throughout which description reference is made toitheiaccmpanying drawings,` in which:

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Fig. 1 is a view of the shielded syringe that I have provided, showing it in a normal unactuated condition. Fig. 2 is a view similar to Fig. 1 showing the shield that I provide as it appears when shifted to expose the needle of the syringe. Fig. 3 is an enlarged detailed sectional view taken through a portion of the structure shown in Fig. l of the drawings. Fig. 4 is a view similar to Fig. 3 showing the parts in the position that they appear in Fig. 2 of the drawings. Fig. 5 is an enlarged sectional view taken as indicated by line 5-5 of Fig. 3, and Fig. 6 is a view of a portion of -the structure showing a modified form of construction.

The present invention involves a syringe or hypodermic injecting device, which structure may vary widely as cir cumstances require. The syringe may be a simple cylinder and piston type of device, and as illustrated in the drawings, may be a chargeable syringe X adapted to be loaded with a carpule or fluid carrying unit Y, and having a plunger Z for operating against the carpule to eject fluid therefrom. As shown, the syringe X carries a needle N that is in communication with the carpule when said carpule is in operating position. It is the needle N for which I provide the shield of the present invention.

The syringe X, as shown, involves an elongate frame 10 having a side opening 11. The forward end of the .frame 10 is provided with a recess 12 for receiving and supporting the carpule Y and with a needle support 13 for mounting the needle N on the frame 10. The rear end of the frame 10 is provided with a head or breech 14 that is shiftable through a pivot 15 to move laterally of the frame 10 so that the carpule Y may be entered into or removed from the rear end of the frame. As shown, the breech 14 carries the plunger Z which is the usual elongate rod-like part that is slidably carried by the breech to enter the frame 10 and to engage with the carpule.

The carpule or fluid carrying unit Y is a cylindrically shaped element having a straight cylindrical outer -wall 16 carried in a bore 17 that extends longitudinally through the frame 10. It will be apparent how the carpule can be applied to or removed from the frame 10. In accordance with common practice, the carpule Y is closed at its ends by plugs or the like, there being a head plug 18 at the forward end thereof and a piston plug 19 at the rear end thereof. The plugs are preferably of soft pliant material, such for example as rubber or the like, so that the plug 18 is penetrable and so that the plug 19 is compressible to have sliding and sealing engagement with the interior of the carpule wall 16. Thus, when the plunger Z is operated to press against the rear end of the carpule Y, the piston plug 19 is moved or shifted to expel fluid from the carpule. It will be apparent that communication is made to the needle N when the carpule Y is initially placed in working position, for example, by means of the needle N piercing the plug 18 of the carpule.

The needle N is shown as an ordinary needle of the type under consideration and may vary to meet with different frame constructions. In the case under consideration, the needle support 13 is in the form of Van elongate boss that projects forwardly fro-m the frame 10. The boss is provided with a central bore 20 for passing the needle N and with external threads 21 for receivingfa coupler element. A seat 22 is provided in the end face of the boss and as in the case illustrated, when the needle is provided with an enlargement 23, the seat 22 engages with the enlargement toposition the needle relative:A to the frame 10 and the carpule Y. As shown, the rear prtion 24 of theneedle is sharpened and extends through the bore 20 to pierce the plug 18 of the carpule and to enter into the carpule. The 'front portion of the needle N is also sharpened and Vprojects forwardly from the enlargement 23.

In accordance with the invention, I have provided a shield S for the needle N, including an outer cover section C and an inner mounting section M therefor, and a control means P that acts to control the position of the cover section C relative to the mounting section M to the end that `only the desired length of needle is exposed. The outer cover C is a tubular element that normally houses the needle N while the mounting M is incorporated with the coupling means for securing the needle N to the frame and acts to shiftably carry the cover C. A positioning means R is provided that normally yieldingly holds the cover C in the unactuated position where it covers or houses the needle N.

The inner mounting M is of tubular construction and projects forwardly from the support 13 and involves generally a base and a slide 31 that projects or continues from the base. The base 30 is in the form of a nut threadedly engaged on the threads 21, there being a socket 32 entering the base from the rear thereof and having a seat 33 for engaging the enlargement 23 to hold it in pressure engagement with the seat 22. Thus, the needle N is securely held in working position on the frame 10. The slide 31 extends from the base 30 to project forwardly from the frame 10 concentric with the axis of the needle N and has a smooth continuous cylindrical wall l35, there being a radial ange at the forward terminal' end thereof that presents a stop shoulder 36. The stop shoulder 36 is of limited radial extent and projects from the exterior of the wall to limit outward or forward movement of the cover C as hereinafter described.

The cover C that I have provided is also a tubular element and is telescopically related to the mounting M to shift axially relative thereto. As shown, the cover C involves generally a body 40, a guide 41 at the forward end of the body and a retainer 42 at the rear end of the body. The retainer 42 is engageable with the slide 31 to direct and control movement of the cover C.

The body of cover C is a cylindrically shaped part closed at its forward end by a front wall 43 and open at `its rear end to engage over the mounting M with substantial clearance. It is to be understood that the body 40 may be telescopically carried in the cylindrically shaped slide 31, if so desired. In the preferred form of the invention, the body 40 is tapered somewhat forwardly and inwardly and is rounded at the front wall 43 to .eliminate sharp corners. In practice, the flange forming the shoulder 36 engages the interior of the body 40 at the -forward end thereof, while the flange has substantial -disposed slots 43 that act to vent the interior of the shield and provide drainage therefrom.

The retainer 42 at the rear of the body 4l) is provided -to secure the cover -C in operating position and to limit the forward extent to which the cover C can be moved or shifted. Theretainer 42 is in the form of a ring threaded onto the exterior of the body 40 at 46 and has an inwardly extending lip 47 that is engageable with the shoulder 36. Thus, the forward movement of the cover C is limited as clearly illustrated in Fig. 3 of the draw* ings. The opening 48 formed by the lip 47 is substantially larger than the diameter of the wall 35 so that the cover C can swing or pivot laterallyas indicated by the arrows 100 in Fig. 3 of the drawings.- In this way, flexibility 'of the needle N, which is many times necessary, is not lost.

The control means P is provided to limit rearward movement or shifting of the cover C relative to the mounting M and involves a step 50 related to one of the shield sections and a stop 51 related to the other shield section. The step 50 is, as illustrated in Figs. l to 5 of the drawings, an arcuate shell-like part that extends rearwardly from the cover C and may be formed integrally with the retainer 42. The step 50 is located at one side of the shield S and is semi-circular in configuration and presents a rearwardly facing abutment wall 53 adapted to engage the stop 51 or the front of the frame 10 as the case may be. In the form of the invention shown in Fig. 6, the step 15d is substantially the same except that it is suiciently large enough in radius to pass over the exterior of the frame 10 of the syringe.

The stop 51, as illustrated in Figs. 1 to 5 of the drawings, is in the form of a pin that is spaced forwardly from the front of the frame 10 and projects laterally of the mounting M on an axis that is normal to the central longitudinal axis of the structure to the end that when the parts are positioned as shown in Figs. 1 and 3 of the drawings, the movement of the cover C is limited,

and to the end that when the parts are positioned as shown in Figs. 2 and 4 of the drawings, the movement of the cover C is extended. It will be apparent that the cover C is simply rotated from one position to the other in order to gain the desired control or exposure of the needle N. In the form of the invention shown in Fig. 6, the stop 151 is carried by an adapter 160 that encompasses the support 13 and is pressed onto the frame 10 of the syringe. In this latter form of the invention, the stop 151 is in the form of a pin that projects forwardly from the front of the frame 10 on an axis parallel to and spaced from the axis of the shield. The stop pin 151 terminates in a flat stop face for engaging the step 150.

The positioning means R is a spring means and involves a light compression spring that acts between the coupling portion of the mounting M and the forward end of the cover C, as shown. A spring seat 60 is formed in the guide 41 with the result that the cover C is normally yieldingly urged to an extended position as clearly shown in Figs. 1 and 3 of the drawings.

From the foregoing, it will be apparent that I have provided an extremely simple and practical shield for a syringe that completely houses the needle thereof when in the normal unactuated position and which yieldingly moves or shifts the exposed needle when desired. Further, the amount of exposure of the needle N is easily controlled by rotation of the cover C of the shield S. It is also to be observed that the flexibility of the needle is not lost since the cover C is mounted to swing laterally when circumstances require. It will also be apparent that the needle N is easily and quickly replaceable by simply unthreading the coupling portion of the mounting M that I have provided.

Having described only typical preferred forms and applications of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modilications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described my invention, I claim:

l. In a syringe of the character described and having a tubular fluid handling needle projecting therefrom, a sectional shield for the needle and including, an inner mounting section, an outer cover section shiftably carried by the mounting section Abetween an extended position and selected retracted positions, control means selectively limiting retraction of the cover section and including a step on one section engageable with a stop on the other section, said section being rotatable relative to each other to selectively position said step, and means normally holding the shield in said extended position to enclose the needle.

2. In a syringe of the character described and having a tubular uid handling needle projecting therefrom, a sectional shield for the needle and including, aninner mounting section, an outer cover section shiftably carried by the mounting section between an extended position and selected retracted positions, control means selectively limiting retraction of Athe cover section and including a step on the cover section engageable with a stop pin on the mounting section, the cover section being rotatable whereby the said step is disengaged from the pin, and means normally holding the shield in said extended position to enclose the needle.

3. In combination, a syringe having a frame with a needle support projecting from the front end thereof and a tubular uid handling needle projecting from the support, and a sectional shield for the needle and including, an inner mounting section carried by said support and securing the needle thereto, an outer cover section shiftably carried by the mounting section to move between extended and retracted positions, control means selectively limiting retraction of the cover section and including a step on one section engageable with a stop on the other section and said sections being rotatable relative to each other to selectively position said step, and means normally holding the shield in said extended position to enclose the needle.

4. In combination, a syringe having a frame with a needle support projecting from the front end thereof and a tubular fluid handling needle projecting from the support, and a sectional shield for the needle and includ ing, an inner mounting section carried by said support and securing the needle thereto, an outer cover section shiftably carried by the mounting section to move between extended and retracted positions, control means selectively limiting retraction of the cover section and including a step on the cover section engageable with a stop pin on the mounting section, the cover section being rotatable whereby the said step is disengaged from the pin, a needle guide freely passing the needle at the for ward end of the cover, and means normally holding the shield in said extended position to enclose the needle.

References Cited in the tile of this patent UNITED STATES PATENTS 268,996 Brink-erben Dec. 12, 1882 1,845,036 Busher Feb. 16, 1932. 2,187,259 Barnum Jan. 16, 1940 2,674,246 Bower Apr. 6, 1954 FOREIGN PATENTS 295,554 Italy Apr. 25, 1932 

